S-10 Runs Bad...help !!!!!!!!!!!!!

[STOVE BOLT]

I Have.
93 Chevy S-10, 2.5, 2wd, 5 Speed.the Problem Is As Follows:
. When First Starting The Engine, It Starts Quickly. Runs Very Nice For A Period Of About 5 Minutes. After It Is Warmed Up, I Can Open The Throtle Approximatly, 25%, And It Stumbles Very Badly. If I Increase The Throtle, It Picks Up Rpm, But Runs Terrabile. Skips, Shakes And All But Quits. If I Let The Throtle Close Completly, It Returns To A Fairly Good Idle.so Far I Have Replaced: The Tps, Cts, And The Egr Valve Vacum Selinoid. No Help. Tonight A Friend Of Mine Took A Vacum Test. It Was 18 At Idle. The Manual Calls For 15-18. So That Is Fine. Next He Disconnected The Vacum Line From The Egr Valve, And It Runs Better. My Question Is , We Connected The Vacum Gauge To The Port On The Valve That Goes To The Egr Valve. Started The Engine, And It Shows Vacum . If The Throtle Is Increased, The Vacum Also Increases. According To The Manual, This Is Not Supposed To Happen. I Think,something Is Telling The Computer It`s Ok To Apply Voltage To The Vacum Valve. Is This True? If It Is Not, Which I Am In Belief Of, What Can Tell The Computer To Apply Voltage To The Vacum Selinoid Valve, At The Wrong Time? I Am At The End Of My Rope With This Truck. By The Way, After This Takes Place, I Get A Code 45. It Is Correct Because The Exhaust Gas Is Very Rich. Any Ideas? I Will Be Eternaly Grateful For Any Light You May Be Able To Shed On This "vixen", S-10 Problem.
Thank You Very Kindly,
Stove Bolt

[Mikado14]

You mentioned "after it is warmed up". You may be going into closed loop operation. If you have a scanner or access to one that read the data stream you will need to see if this is so. If it is, check the response of the O2 sensor. If it has over 100K miles and has never been changed, it wouldn't hurt at all.

[dmbrisket 51]

mike is right it could be a computer problem if the moter must worm up first, it also is possible that the roter cap and or spark plugs have started going bad, check those befour you buy a lot in new parts, and check the o2 sencor, if its dirty you can clean it with some "sea foam" cleaner (like carb and choke cleaner just not a strong) or if it is bad you can replace it, not sure with the 92, but the 02 is in the manifold and not behind the cat correct?

[STOVE BOLT]

Originally Posted by Mikado14

You mentioned "after it is warmed up". You may be going into closed loop operation. If you have a scanner or access to one that read the data stream you will need to see if this is so. If it is, check the response of the O2 sensor. If it has over 100K miles and has never been changed, it wouldn't hurt at all.

WELL, THE OXEGEN SENSOR HAS BEEN REPLACED TWICE. FORGOT TO MENTION IT. I DO GET A CODE 45, THAT SAYS RICH MIXTURE, REPLACE OZYGEN SENSOR. I HAVE 2 TIMES TO NO AVAIL. I HAVE NO IDEA, BUT, HAVE BEEN TOLD, THERE IS NO SCANNER FOR THIS OLD PIECE. IT`S A `93. HAS SELF DIAGNOSTIC CAPABILITIES. I ONLY GET THE CODE 45. AFTER DISCONNECTING THE BATTERY , THIS CLEARS ITSELF, BUT, RETURNS NEXT TIME ENGINE IS STARTED.

[Mikado14]

Ok, I'm going to tell you something against my own advice. I don't like to tell anyone to just change something but I assume you have no way of reading the data stream.

There are two sensors for temp, one for the guage and one for the computer. You very well may have a bad temp sender for the computer. It's cheap enough if you wish to change it out. I say this because if it were bad or off value, the computer will send a rich mixture at all times and it won't go into a closed loop state.

[STOVE BOLT]

Originally Posted by Mikado14

Ok, I'm going to tell you something against my own advice. I don't like to tell anyone to just change something but I assume you have no way of reading the data stream.

There are two sensors for temp, one for the guage and one for the computer. You very well may have a bad temp sender for the computer. It's cheap enough if you wish to change it out. I say this because if it were bad or off value, the computer will send a rich mixture at all times and it won't go into a closed loop state.

OK MIKE. I HEAR YA. I DID IN FACT CHANGE THE CTS (coolant temp sensor).IT DID NOT HELP. I ALSO REPLACED THE "THROTLE POSISTION SENSOR" ,THIS DONE NOTHING EITHER. I HAVE NO WAY OF KNOWING WHAT DATA MAY BE STORED IN THAT DAMN COMPUTER, BUT, LIKE I SAID BEFORE, I WAS TOLD THAT THE DATA CAN NOT BE DOWNLOADED. MAYBE SO, MAYBE NOT SO, BUT, I AM GONNA DUMP THIS THING IF I CAN`T GET IT RUN LIKE IT SHOULD.
THANKS AGAIN MIKE. I APPRECIATE YOUR INPUT.
STOVE BOLT

[BlazerLT]

Dumb question, but have you replaced the plugs lately?

Have you removed the EGR valve and cleaned it out and made sure it wasn't clogged with carbon?

[rustbucket]

If you got a little electronics skills and some parts, you can make a scanner cable that could plug to a serial port on a computer and get the data. I made a cable that works on my 93 2.8L s10 and my 87 buick lesabre. See this web site : http://w1.601.telia.com/~u60113744/s...dl/winaldl.htm
Heres a screen shot of it when I was driving:

[STOVE BOLT]

Originally Posted by BlazerLT

Dumb question, but have you replaced the plugs lately?

Have you removed the EGR valve and cleaned it out and made sure it wasn't clogged with carbon?

I`VE DONE ALL THE USUAL THINGS ONE DOES WHEN THESE KINDS OF PROBLEMS COME UP.
I HAVE REPLACED THE FOLLOWING :
1. PLUGS, CAP, ROTOR, WIRES.
2. CLEANED , TESTED, EGR VALVE.OK.
3. CTS, COOLANT TEMP. SENSOR.
4. VACUM SELINOID, FOR EGR .
5. TPS, FUEL FILTER, PUMP, AND LINES. ALL OK.
THATS NOT A DUMB QUESTION. THE ONLY DUMB ONES ARE THOSE THAT DON`T GET ASKED.
THANKS, STOVE BOLT

[STOVE BOLT]

Originally Posted by rustbucket

If you got a little electronics skills and some parts, you can make a scanner cable that could plug to a serial port on a computer and get the data. I made a cable that works on my 93 2.8L s10 and my 87 buick lesabre. See this web site : http://w1.601.telia.com/~u60113744/s...dl/winaldl.htm
Heres a screen shot of it when I was driving:

http://w1.601.telia.com/~u60113744/...ldl/winaldl.htm
^THIS WEB SITE IS IN A FOREIGN LANGUAGE. I CAN`T UNDERSTAND IT.

[gmtech04]

Originally Posted by STOVE BOLT

I Have.
93 Chevy S-10, 2.5, 2wd, 5 Speed.the Problem Is As Follows:
. When First Starting The Engine, It Starts Quickly. Runs Very Nice For A Period Of About 5 Minutes. After It Is Warmed Up, I Can Open The Throtle Approximatly, 25%, And It Stumbles Very Badly. If I Increase The Throtle, It Picks Up Rpm, But Runs Terrabile. Skips, Shakes And All But Quits. If I Let The Throtle Close Completly, It Returns To A Fairly Good Idle.so Far I Have Replaced: The Tps, Cts, And The Egr Valve Vacum Selinoid. No Help. Tonight A Friend Of Mine Took A Vacum Test. It Was 18 At Idle. The Manual Calls For 15-18. So That Is Fine. Next He Disconnected The Vacum Line From The Egr Valve, And It Runs Better. My Question Is , We Connected The Vacum Gauge To The Port On The Valve That Goes To The Egr Valve. Started The Engine, And It Shows Vacum . If The Throtle Is Increased, The Vacum Also Increases. According To The Manual, This Is Not Supposed To Happen. I Think,something Is Telling The Computer It`s Ok To Apply Voltage To The Vacum Valve. Is This True? If It Is Not, Which I Am In Belief Of, What Can Tell The Computer To Apply Voltage To The Vacum Selinoid Valve, At The Wrong Time? I Am At The End Of My Rope With This Truck. By The Way, After This Takes Place, I Get A Code 45. It Is Correct Because The Exhaust Gas Is Very Rich. Any Ideas? I Will Be Eternaly Grateful For Any Light You May Be Able To Shed On This "vixen", S-10 Problem.
Thank You Very Kindly,
Stove Bolt

Did disconnecting the vacuum line to EGR valve solve the problem ?
trouble code 45 is a RICH EXHAUST CODE, which could be caused by
the EGR valve opening at idle or a defective Oxygen sensor,Tempature
sensor,stuck Injector(s)....you really need to take your vehicle to a
Dealer and let them put the Scan Tool (Tech II) on it to check the sensor's operation.

[rustbucket]

I guess I have a language pack installed on my pc, the website is english to me. Here is a picture of the cable you need to build. If you are still interested, I can email you the install.
This only works for GM obd1 cars/trucks (and probably not all of them)

[STOVE BOLT]

WELL, I CHANGED THE ATS (air temp sensor))AND IT DONE ABSOLUTLY NOTHING. ANYWAY, I HAVE A FRIEND WITH A "SNAP ON" COMPUTER DATASTREAM DOWNLOAD READER, THAT SAYS, IF THIS DON`T FIND YOUR PROBLEM, IT CAN`T BE FOUND. I`LL LET YOU GUYS KNOW AS SOON AS HE GETS AROUND TO CHECKING IT OUT FOR ME.

[BlazerLT]

Please take the caps lock off.

[96Rivman]

It could be a plugged converter.